Ok she wants a better life? She could try the H2A or H2B programs. https://mx.usembassy.gov/h-2-visa-information/
If she wants to marry you then you file the I-129F for a fiancé visa and you wait. She won't be able to work for some time in the US, probably over a year. So you might consider getting married and fling a spousal visa.
That is for a B2 visa. But if she has had one before is a few weeks. She can't enter the US with the intent to adjust nor can she work in the US.
Not an option and could cause more of a delay.
Glad you are here doing your research. Unless you are also a resident in Mexico and needing to return to the US for a job, there aren't any options do get this done quickly.